Rotary pumps a device for reversing the rotation of the pump without reversing its direction of suction



y 1959 A F. ENEMARK 2,893,323

ROTARY PUMPS EVICE FOR REVERSING THE ATION OF THE PUM P WITH REVERSING IT IRECTION SUCTION Filed Jan. 1957 Fig.7

States Patent ROTARY PUMPS A DEVICE FOR REVERSING THE ROTATION OF THE PUMP WITHOUT REVERS- ING ITS DIRECTION OF SUCTION Arne Fromm Enemark, Sonderborg, Denmark, assignor to Danfoss Ved ingenior Mads Clausen Elsmark, Nordborg, Denmark, a Danish firm The invention relates to a device in rotary pumps for reversing the rotation of the pump without reversing its direction of. suction.

Devices .of the said kind are known, but they consist of displaceable valves or swivelling cocks which are rather complicated and unsuitable for manufacture in small dimensions. Furthermore, they are relatively costly to manufacture and require a rather accurate adaptationin order to be reliable in operation.

It is. also .known to remove the' pump body of the pump and to turn it by 180 degrees in relation to the pump casing and then remounting the pump body. The suction and the pressure passages of the pump are thereby exchanged so that the desired effect is obtained, but such an exchange is relatively complicated to perform and it is generally disadvantageous to perform it-where the pump is installed.

'It is the object of the invention to devise. a simple and robust device of the aforesaid kind which is suitable for mass production in small and largedimensions alike and having none of the aforesaid drawbacks.

'An essential feature of a device according to the in vention is that the two feeding pipes of the pump by means of two interchangeable plugs which fit snugly in the pump casing are connected to two anterooms formed in the'pump casing. ,The said anterooms are connected to' an inlet pipe auda discharge pipe, respectively, and the said plugs have, each a transverse boring which through a longitudinal passage communicates with one end. surface of the plug, the said boring and the said passage having such a location that when the plugs are interchanged, the connection of the two feeding pipes is interchanged in relation to the inlet and discharge pipings,

As a result, the rotation of the pump may bereversed without its direction of suction being reversed, if only simultaneously the ,two plugs are interchanged. i .In an embodiment of the device according to the invention the first anteroom has a wall in common with the other anteroom, and the two interchangeable plugs are passed through the first anteroom, the second anteroom and the common wall in which they fit tightly, and the transverse boring of the first plug is located opposite the interior of the first anteroom, whereas the transverse boring of the second plug is located opposite the interior of the second anteroom, while the longitudinal borings of both plugs'open each in their separate feeding pipe. As a result, the two anterooms may be built together to form a unit which in simple manner may be connected to the feed pipe of the pump, the two plugs being furthermore accessible from the outer side of the unit.

vIn another embodiment of the device according to the invention the anterooms are located on diametrically opposite outer sides of the pump casing, each transverse boring of the plugs being furthermore located opposite its separate opening in the feed pipe of the pump, the longitudinal passages of the plugs each opening in their separate anteroom.

The result obtained is a location of the anterooms that 2,893,323 Patented July 7, 1959 is advantageous for certain uses, the said anterooms being bounded by covers for the pump casing and the plugs being only accessible after one of these covers having been removed.

The invention will now be further described with reference to the drawing which shows a device in rotary pumps according to the invention.

Fig. 1 shows one embodiment of the invention.

Fig. 2 shows a second embodiment of the invention.

In the drawing 1 is a rotary pump of any kind whatever, for example as shown a gear-wheel pump, the pumping direction of which is reversed when its rotation is-reversed. The pump 1 has two feed pipes 2, 3 which, when the pump rotates in the direction indicated by an arrow, act as suction pipe and pressure pipe, respectively. Both the suction pipe 2 and the pressure pipe 3 are connected to the first anteroom 4 which, for example, may be built-in in the pump casing (not shown). The first anteroom 4 has a wall common with the second anteroom 5, which may likewise be built-in in the pump casing. Through the two anterooms 4 and 5 and through the common wall are passed two tightly fitted interchangeable plugs 6, 7 which are accessible from the outerside of the anterooms and which, for example, may be provided with screw or bolt heads located outside the outer side. The said plugs 6, 7 fit tightly into the two 7 feed pipes 1, 2 and may, for example, be attached to the two pipes by means of a screwthread provided in the said pipes as shown in the drawing or in the outer wall of the anterooms or in the common wall. The tight fitting of the plugs at the places where there is no screwthreading may be obtained by means of smooth cylinder surfaces, and between the screw or bolt heads of the plugs and the outer sides of the anterooms may be used packings (not shown). Each of the plugs 6, 7 is provided with a transverse boring 8, 9 which in the first plug 6, is located opposite the interior of the first anteroom 4 and in the second plug 7 opposite the interior of the second anteroom 5. Both plugs are provided with a longitudinal passage, 10 and 11, respectively, which opens into the suction pipe 2 and into the pressure pipe 3, respectively. One of the anterooms, for example, the first anteroom 4, may by means of a piping (not shown) communicate with a container containing the liquid or gas which is to be pumped to the other anteroom 5 and further to another piping (not shown) for example, to the place of use. The pump 1 may for example be assumed to be used as fuel pump in an oil burner, and, if so, the container may be the storage tank of the oil burner and the place of use may be the burner of the oil-firing installation. In such oil burners the pump may, for example, be coupled to the fan of the oil burner, the direction of rotation of which fan is generally given beforehand, and if the direction of rotation of the fan coincides with the direction of rotation for the pump as indicated by the arrow, the oil will be sucked from the container to the first anteroom 4 and through the boring 8 and the passage 10 to the suction pipe of the pump. From the pressure pipe 3 of the pump the oil will pass through the passage 11 and the boring 9 in the plug 7 to the other anteroom and through the other piping be fed to the burner of the oil-firing installation.

If, on the contrary, the fan for cooperating with the pump rotates in such direction that the pump I mounted on the shaft of the fan will move opposite the arrow, the pump cannot be used straight away. However, this can be remedied by simply interchanging the two plugs 6 and 7, whereby the oil from the first anteroom 4 will pass through the boring 8 and the passage 10 in the plug 6 which is now placed to the left in the drawing, and oil is "now sucked in through the former pressure pipe 3 to be delivered by the pump to the former suction pipe 2,

from which the oil is conveyed through the passage 11 and theboring 9 in the plug 7, which is now to the right in the drawing, to the second anteroom 5 and hence to the burner of the installation. On reversing the rotation 9f the pump it is thus possible to reverse the directionof suction of thepurnp by interchanging the plugs 6 and 7.

In another embodiment of the device according to the invention as shown in :Figure 2 the anterooms 4,5 are located on diametrically opposite outer sides of the pump casing 1, 2, and the transverse borings 8, 9 of the plugs 6, 7 are each located opposite their separate openings in the feeding pipes of the pump, 2 and 3, respectively. The longitudinal passages (10 and 11) of the plugs are formed in the plugs in such manner that they each open in their separate anterooms, 4 and 5, respectively, which may be limited by covers 13, 14 for the pump casing or in other manner be designed in connection with the pump casing. The plugs 6, 7 fit tightly in passages 15, 16 which in the pump casing both lead from one anteroom to the other and may be attached by screwthrcading provided in the said passages. When the plugs 6, 7 are interchanged, the pump may thus be used when the direction of rotation of .the pump is opposite that indicated by an arrow in Figure 2, without the direction of suction of the pump being reversed.

I claim:

1. In a rotary pump having a body defining a pump chamber and a rotor rotatable therein, a first conduit communicating with one portion of said chamber and a second conduit communicating with another portion of said chamber, each of said conduits being adapted for selective use as the suction and pressure conduits of the pump, means defining a first auxiliary chamber positioned to communicate with said pump chamber, means defining a second auxiliary chamber positioned to communicate with said pump chamber, first removable plug means received in said first conduit, second removable plug means received in said second conduit, said first plug means being provided with an internal passageway communicating with the conduit in which said first plug means is received and with said first auxiliary chamber, and said second plug means being .formed with an internal passageway communicating with the conduit in which said second plug means is received and with said second auxiliary chamber, said first and said second plug means being interchangeable in said first and said second conduits for selectively connecting each of said conduits with said first auxiliary chamber and said second auxiliary chamber, and said auxiliary chambers being adapted to communicate selectively with the source of fluid to be pumped and the receiving means for the fluid pumped by said pump.

2. In a rotary pump having a body defining a pump chamber and a rotor rotatable therein, a first conduit communicating with one portion of said chamber and a second conduit communicating with another portion of said chamber, each of said conduits being adapted for selective use as the suction and pressure conduits of the pump, means defining a first auxiliary chamber in said body positioned to communicate with said pump chamber, means defining a second auxiliary chamber in said body positioned to communicate with said pump chamber, said auxiliary chambers having a common wall, first removable plug means received in said first conduit and extending through said auxiliary chambers and said common wall, second removable plug means received in said second conduit and extending through said auxiliary chambers and said common wall, said first plug means being provided with an internal passageway communicating with the conduit in which said first plug means is received and with said first auxiliary chamber, and said second plug means being formed with an internal passageway communicating with the conduit in which said s'e'c'ondplug means is received and with said second auxiliary chamber, said first and said second plug means being interchangeable 'in' said first and said second conduits for selectively connecting each of said conduits with said first auxiliary chamber and said second auxiliary chamber, and said auxiliary chambers being adapted to communicate selectively with the source of fluid to be pumped and the receivingmeans for the fluid pumped by said pump.

3. In a rotary pump having a body defining a pump chamber and a rotor rotatable therein, a first conduit communicating with one portion of said chamber and a second conduit communicating with another portion of said chamber, each of said conduits being adapted for selective use as the suction and pressure conduits of the pump, means defining a first auxiliary chamber in said body positioned to communicate with said pump chamber, means defining a second auxiliary chamber in said body positioned to communicate with said pump chamber, said auxiliary chambers being on opposite sides of said body, first removable plug means received in said first conduit and extending between said auxiliary chambers, second removable plug means received in said second conduit and extending between said auxiliary chambers, said first plug means being provided with an internal passageway communicating with the conduit in which said first plug means is received and with said first auxiliary chamber, and said second plug means being formed with an internal passageway communicating with the conduit in which said second plu'g means is received and with said secondauxiliary chamber, said first and said second plug means being interchangeable in said first and said second conduits for selectively connecting each of said conduits with said first auxiliary chamber and said second auxiliary chamber, and said auxiliary chambers being adapted to communicate selectively with the source of fluid to be pumped and the receiving means for the fluid pumped by said pump. i

4. 'In a rotary pump having a body defining a pump chamber and a rotor rotatable therein, a first conduit communicating with one portion of said chamber and a second conduit communicating with another portion of said chamber, each of said conduits being adapted for selective use as the suction and pressure "conduits of the pump, means defining a first auxiliary chamber in said body positioned to communicate with said .pump chamber, means defining a second auxiliary chamber in said body positioned to communicate with said pump chamber, first removable plug means threadedly received in said first conduit, second removable plug means threadedly received said second conduit, said first plug means being provided with an internal passageway communicating with the conduit in which said first plug means is received and with said first auxiliary chamber, and said second plug means being formed with an internal passageway communicating with the conduit in which said second plug means is received and with said second auxiliary chamber, said first and said second plug means being interchangeable in said first and said second conduits for selectively connecting each of said conduits with said first auxiliary chamber and said second aux iliary chamber, and said auxiliary chambers being adapted to communicate selectively withthe source of fluid to be pumped and the receiving means for the fluid pumped by said pump.

References .Cited in the file of this patent UNITED STATES PATENTS 2,347,862 Wishart May '2, 1 944 2,671,410 -Wahlmarl Mar. 9, 19154 a FOREIGN PATENTS 167,074' Australia Qlfeb. 23, 1956 861,119 France Oct. 22, 1940 

